Camera unit and multimedia information appliance including camera unit

ABSTRACT

A camera unit includes an image sensor, an image signal processor, an application processor and a frame memory. The image sensor receives an optical signal from a lens unit and converts it into an electrical signal. The image signal processor converts the electrical signal into an image signal, and includes a first sub block controlling the image sensor and the lens unit and a second sub block receiving and processing the image signal from the first sub block. The application processor receives the image signal from the second sub block and further processes the image signal. The frame memory is connected to the second sub block and the application processor to store the processed image signal. The image sensor and the first sub block constitute a first chip not connected to the frame memory, and the second sub block and the application processor constitute a second chip connected to the frame memory.

PRIORITY STATEMENT

A claim of priority is made under 35 U.S.C. §119 to Korean PatentApplication No. 10-2009-0047513, filed on May 29, 2009, in the KoreanIntellectual Property Office, the subject matter of which is herebyincorporated by reference.

BACKGROUND

The present disclosure relates to a camera unit and a multimediainformation appliance including the camera unit. More particularly, thepresent disclosure relates to a camera unit capable of reducing thenumber of memories and improving image quality, and a multimediainformation appliance including the camera unit.

As additional applications and capabilities are developed for mobilecommunication devices, secondary functions unrelated to wirelesscommunications, such as camera modules or units, multimedia players, andthe like, are being added to mobile communication devices. Further, thescope of functionality of the camera units has broadened throughimprovement of display screens of the mobile communication device, aswell as implementation of high-speed communication. That is, the supplyof mobile communication devices equipped with camera units is steadilyincreasing, and the performance of the camera units (e.g., pixeldensity, etc.) mounted in the mobile communication units is improving.

A typical camera unit includes an image sensor, an Image SignalProcessor (ISP), and an application processor. Generally, the imagesensor converts optical signals received from a lens unit intoelectrical signals, and outputs the electrical signals. The ISP convertsthe electrical signals output from the image sensor into image signals,and the application processor processes the image signals received fromthe ISP.

SUMMARY

The present disclosure generally describes a camera unit for reducingthe total number of memories and improving image quality. Also, thepresent disclosure describes a multimedia information appliance thatincludes the camera unit.

Embodiments of the inventive concept provide a camera unit, including animage sensor, an image signal processor, an application processor and aframe memory.

The image sensor receives an optical signal from a lens unit andconverts the optical signal into an electrical signal. The image signalprocessor converts the electrical signal into an image signal, andincludes a first sub block controlling the image sensor and the lensunit, and a second sub block receiving the image signal from the firstsub block and processing the image signal. The application processorreceives the image signal from the second sub block and furtherprocesses the image signal. The frame memory is connected to the secondsub block and the application processor to store the processed imagesignal from at least one of the second sub block and the applicationprocessor. The image sensor and the first sub block constitute a firstchip not connected to the frame memory, and the second sub block and theapplication processor constitute a second chip connected to the framememory.

Other embodiments of the inventive concept provide a multimediainformation appliance, including an image sensor, an image signalprocessor, an application processor, a frame memory and an imagedisplay.

The image sensor receives an optical signal from a lens unit andconverts the optical signal into an electrical signal. The image signalprocessor converts the electrical signal into an image signal, andincludes a first sub block controlling the image sensor and the lensunit, and a second sub block receiving the image signal from the firstsub block and performing first processing of the image signal. Theapplication processor receives the processed image signal from thesecond sub block and performs second processing of the processed imagesignal. The frame memory is connected to the second sub block and theapplication processor to store the image signal processed by at leastone of the second sub block and the application processor. The imagedisplay receives the processed image signal from the applicationprocessor and displays an image corresponding to the received imagesignal. The image sensor and the first sub block constitute a sensorchip not connected to the frame memory, and the second sub block and theapplication processor constitute a processor chip connected to the framememory.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the inventive concept, and are incorporated in andconstitute a part of this specification. Exemplary embodiments of theinventive concept will be described with reference to the attacheddrawings, in which:

FIG. 1 is a block diagram illustrating a camera unit, according to anexemplary embodiment of the inventive concept;

FIG. 2 is a block diagram illustrating a first sub block and a secondsub block of FIG. 1, according to an exemplary embodiment of theinventive concept; and

FIG. 3 is a block diagram illustrating a multimedia informationappliance, according to an exemplary embodiment of the inventiveconcept.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Various embodiments of the inventive concept will now be described morefully with reference to the accompanying drawings, in which illustrativeembodiments are shown. The inventive concept, however, may be embodiedin various different forms, and should not be construed as being limitedonly to the illustrated embodiments. Rather, these embodiments areprovided as examples, to convey the inventive concept to one skilled inthe art. Accordingly, known processes, elements, and techniques are notdescribed with respect to some of the embodiments. Throughout thedrawings and written description, like reference numerals will be usedto refer to like or similar elements.

FIG. 1 is a block diagram illustrating a camera unit, according to anexemplary embodiment of the inventive concept.

Referring to FIG. 1, a camera unit 100 includes an image sensor 120, anImage Signal Processor (ISP) 130, an application processor 140, and aframe memory 150.

The image sensor 120 is configured to receive optical signals from alens unit (not shown) corresponding to images, and to convert theoptical signals into electrical signals. The electrical signalsgenerated from the image sensor 120 are transmitted to the ISP 130.

The ISP 130 is configured to convert the electrical signals output fromthe image sensor 120 into image signals. For example, the ISP 130 mayconvert the electrical signals output from the image sensor 120 intodigital image signals, and output the digital image signals. Also, theISP 130 may control operations of the image sensor 120 and the lensunit.

The application processor 140 is configured to perform variousprocessing functions in order to display the image signals. In addition,the application processor 140 may compress and decompress the imagesignals supplied from the ISP 130.

FIG. 1 depicts an embodiment of the inventive concept in which the ISP130 includes a first sub block 131 and a second sub block 132, forexample. The first sub block 131 includes function blocks forcontrolling the image sensor 120 and the lens unit, and therefore thefirst sub block 131 does not require use of the frame memory 150. Incomparison, the second sub block 132 includes function blocks forprocessing the image signals, and therefore the second sub block 132 mayrequire the frame memory 150 to store the processed image signals.

As shown in FIG. 1, the image sensor 120 and the first sub block 131constitute a sensor chip C1, and the application processor 140 and thesecond sub block 132 constitute a processor chip C2, for example. Theframe memory 150 is connected to the processor chip C2, which includesthe second sub block 132 and the application processor 140. Therefore,the second sub block 132 and the application processor 140 may storesignals in the frame memory 150, or may read out stored signals from theframe memory 150. The frame memory 150 is not connected to the sensorchip C1.

Since the first sub block 131 is directly connected to the image sensor120, the first sub block 131 may easily tune parameter values of the ISP130 in consideration of the characteristics of the image sensor 120 andthe lens unit. Meanwhile, the second sub block 132 is provided in theprocessor chip C2 to use the frame memory 150, while being connected tothe image sensor 120 through the first sub block 131. Accordingly, sincethe frame memory 150 is connected to only the processor chip C2, but noframe memory is connected to the sensor chip C1, the total number offrame memories provided in the camera unit 100 is reduced.

A data line L1 and a control line L2 may be provided as interfacesbetween the first sub block 131 and the second sub block 132. The dataline L1 transmits the image signals output from the first sub block 131to the second sub block 132. The control line L2 transmits processingresults of one or more function blocks of the first sub block 131 tocorresponding function blocks of the second sub block 132, and transmitsprocessing results of one or more function blocks of the second subblock 132 to corresponding function blocks of the first sub block 131.For example, the control line L2 may include high speed-serialperipheral interface (HS-SPI), which has a small number of lines andtransmits signals at a relatively high speed, although otherimplementations of the control line L2 may be included without departingfrom the scope of the present teachings.

FIG. 2 is a block diagram illustrating the first sub block and thesecond sub block of FIG. 1, according to an exemplary embodiment.

Referring to FIG. 2, the first sub block 131 includes a gain controlblock 131 a, an auto focus block 131 b, and an auto exposure controlblock 131 c. The gain control block 131 a adjusts signal strength ofsignals output from the image sensor 120. The auto focus block 131 bautomatically adjusts focus of the lens unit. The auto exposure controlblock 131 c adjusts an exposure time of the image sensor 120 to adjustautomatically a brightness of the image sensor 120 automatically.

The second sub block 132 includes a noise reduction block 132 a, a facedetection block 132 b, and a digital image stabilizer block 132 c. Thenoise reduction block 132 a removes noise using one or more frames ofimage signals. For example, in an embodiment of the inventive concept,the noise reduction block 132 a may include a 3D noise reduction blockthat removes the noise using multiple frames of image signals. The facedetection block 132 b detects a human face of the subject, whenappropriate, from an image. The digital image stabilizer block 132 cperforms a function of inhibiting the effects of hand tremor of thecamera unit operator or other undesirable shaky movement.

The first and second sub blocks 131 and 132 may exchange data throughthe control line L2. For example, when International StandardsOrganization (ISO) sensitivity is adjusted, the signal strengths of theimage signals received from the image sensor 120 need to be increased inthe gain control block 131 a. In this case, since noise also increasesduring adjustment of the signal strengths of the image signals, thenoise reduction block 132 a should be notified that the noise hasincreased. Accordingly, the image signals and/or the adjusted signalstrengths may be transmitted to the noise reduction block 132 a througha first control line L2-1, and the noise reduction block 132 a mayperform a strong filtering.

Also, the auto focus block 131 b may be notified of the position of theface of the subject, as recognized by the face detection block 132 b,through a second control line L2-2. Accordingly, the auto focus block131 b is able to control focusing, centering around a portion of therecognized face.

Parameters used in the auto exposure control block 131 c are transmittedto the digital image stabilizer block 132 c through a third control lineL2-3. If a shutter speed is reduced by the auto exposure control block131 c, spots may be generated on the image due to hand tremor, forexample. Accordingly, when information on the shutter speed istransmitted to the digital image stabilizer block 132 c, the degree ofthe hand tremor correction may be adjusted using the information on theshutter speed.

In addition to the control line L2, which exchanges control data, thedata line L1, which transmits image signals, may be provided between thefirst and second sub blocks 131 and 132, as discussed above.Accordingly, each of function blocks may use information of thecorresponding function blocks.

Although not shown in FIG. 2, in various embodiments, the first subblock 131 may further include a shading correction block, an RGBinterpolation block, a color space conversion block, a gamma correctionblock, an auto white balance block, and/or a hue control block.

Also, although not shown in FIG. 2, it would be apparent to one ofordinary skill in the art that any of the function blocks requiring dataexchanges with function blocks of the second sub block 132 may beconnected to the corresponding function blocks.

FIG. 3 is a block diagram illustrating a multimedia informationappliance, according to another exemplary embodiment of the inventiveconcept.

Referring to FIG. 3, a multimedia information appliance 300 includes acamera unit 100 and an image display unit 200. The configuration of thecamera unit 100 is substantially the same as that described withreference to in FIG. 1, and therefore detailed description thereof willnot be repeated.

In the depicted embodiment, the image display unit 200 includes an LCDcontroller 210, a frame memory 220, an LCD driver 230, and an LCD panel240. The LCD controller 210 is connected to the application processor140 and/or the frame memory 150 of the camera unit 100 to receive theimage signals, and converts a data format of the image signals inaccordance with interface specifications with the LCD driver 230. Also,the LCD controller 210 outputs various control signals necessary for anoperation of the LCD driver 230.

In the depicted embodiment, the frame memory 220 is connected to the LCDcontroller 210. Accordingly, the LCD controller 210 may write the imagesignal in the frame memory 220 and read out the stored image signal fromthe frame memory 220.

The LCD driver 230 outputs a data signal and a gate signal necessary forthe operation of the LCD panel 240 in response to the image signal andthe various control signals supplied by the LCD controller 210.Accordingly, the LCD panel 240 may display an image transmitted from thecamera unit 100 in response to the data signal and the gate signal.Although not shown, the LCD driver 230 may include a gate driveroutputting the gate signal and a data driver for outputting the datasignal.

In accordance with embodiments of the camera unit and the multimediainformation appliance including the same, an image signal processor maybe divided into a first sub block, including function blocks forcontrolling a lens unit and an image sensor, and a second sub block. Aframe memory is connected only to a process chip which includes thesecond sub block and an application processor, but not to a sensor chipwhich includes the first sub block and the image sensor. Therefore, thenumber of components (e.g. memories) of the camera unit is reduced,without affecting performance of the camera unit.

The above-disclosed subject matter is to be considered illustrative andnot restrictive, and the appended claims are intended to cover all suchmodifications, enhancements, and other embodiments, which fall withinthe true spirit and scope of the inventive concept. While the presentinventive concept has been described with reference to exemplaryembodiments, it will be apparent to those skilled in the art thatvarious changes and modifications may be made without departing from thespirit and scope of the present teachings. Therefore, it should beunderstood that the above embodiments are not limiting, butillustrative.

What is claimed is:
 1. A camera unit comprising: an image sensorreceiving an optical signal from a lens unit and converting the opticalsignal into an electrical signal; an image signal processor convertingthe electrical signal into an image signal, the image signal processorcomprising a first sub block controlling the image sensor and the lensunit, and a second sub block receiving the image signal from the firstsub block and processing the image signal; an application processorreceiving the processed image signal from the second sub block andfurther processing the image signal; a frame memory connected to thesecond sub block and the application processor to store the processedimage signal from at least one of the second sub block and theapplication processor; a data line transmitting the image signal outputfrom the first sub block to the second sub block; and a control linetransmitting processing results of the first sub block to the second subblock, and transmitting processing results of the second sub block tothe first sub block, wherein the image sensor and the first sub blockare formed in a first chip not connected to the frame memory, and thesecond sub block and the application processor are formed in a secondchip connected to the frame memory.
 2. The camera unit of claim 1,wherein the first sub block comprises function blocks that do not usethe frame memory, and the second sub block comprises function blocksthat use the frame memory.
 3. The camera unit of claim 1, wherein thecontrol line comprises a high speed-serial peripheral interface(HS-SPI).
 4. The camera unit of claim 1, wherein the first sub blockcomprises: a gain control block adjusting a signal strength of theelectrical signal output by the image sensor; an auto focus blockautomatically adjusting a focus of the lens unit; and an auto exposurecontrol block controlling an exposure time of the image sensor to adjustautomatically a brightness of the image sensor.
 5. The camera unit ofclaim 4, wherein the second sub block comprises: a noise reduction blockremoving noise using one or more frames of the image signal; a facedetection block recognizing a human face; and a digital image stabilizerblock inhibiting an effect of hand tremor.
 6. The camera unit of claim5, wherein the electrical signal having the signal strength adjusted bythe gain control block is transmitted to the noise reduction blockthrough the control line.
 7. The camera unit of claim 5, wherein signalsrecognizing the human face by the face detection block are transmittedto the auto focus block through the control line.
 8. The camera unit ofclaim 5, wherein parameters used in the auto exposure control block aretransmitted to the digital image stabilizer block through the controlline.
 9. A multimedia information appliance comprising: an image sensorreceiving an optical signal from a lens unit and converting the opticalsignal into an electrical signal; an image signal processor convertingthe electrical signal into an image signal, the image signal processorcomprising a first sub block controlling the image sensor and the lensunit, and a second sub block receiving the image signal from the firstsub block and performing first processing of the image signal; anapplication processor receiving the processed image signal from thesecond sub block and performing second processing of the processed imagesignal; a frame memory connected to the second sub block and theapplication processor for storing the processed image signal from atleast one of the second sub block and the application processor; animage display receiving the processed image signal from the applicationprocessor and displaying an image corresponding to the received imagesignal, wherein the image sensor and the first sub block are formed in asensor chip not connected to the frame memory, and the second sub blockand the application processor are formed in a processor chip connectedto the frame memory; a data line transmitting the image signal outputfrom the first sub block to the second sub block; and a control linetransmitting processing results of the first sub block to the second subblock, and transmitting processing results of the second sub block tothe first sub block.